High power electron tube with multiple locked-in magnetron oscillators



June 6, 1967 a. EPSZTEIN 3,324,341

HIGH POWER ELECTRON TUBE WITH MULTIPLE LOCKED IN MAGNETRDN OSCILLATORS Flled Nov 14 1961 '7 Sheets-Sheet 1 FIG. 2

awn R m E 5 NT aufiM/m VP miya M w.

June 6, 1967 B. EPSZTEIN 3,324,341

HIGH POWER ELECTRON TUBE WITH MULTIPLE LOCKED-IN MAGNETRON OSCILLATORS Filed Nov. 14, 1961 7 Sheets-Sheet 2 INVENTOR B. EPSZTE/N ATTORNEY B. EPS EIN 3,324,341 HIGH POWER ELECTRON BE TH MULTIPLE LOCKED-IN MAGNETRON O LLATORS 7 Sheets-Sheet :5

June 6, 1967 Filed Nov. 14, 1961 Flaw A s a A 7 INVENTOR B. EPSZTE/N AT ORNEY June 6, 1967 B. EPSZTERN 3,324,341

HIGH POWER ELECTRON TUBE WITH MULTIPLE LOCKED-IN MAGNETRON OSCILLATORS Filed Nov. 14, 1961 7 Sheets-Sheet 4.

FIG, |NVENTOR B.EPSZTEIN By Wa. ATTOR E June 6, 1967 B. EPSZTEIN. 3,324,341

HIGH POWER ELECTRON TUBE WITH MULTIPLE LOCKED-IN MAGNETRON OSCILLATORS Filed Nov. 14, 1961 '7 Sheets-Sheet 5 INVENTOR B. EPSZTEIN June 6, 1967 B. EPSZTEIN 3,324,341

HIGH POWER ELECTRON TUBE WITH MULTIPLE LOCKED-IN MAGNETRON OSCILLATORS 7 Sheets-Sheet 6 Filed Nov. 14, 1961 mvam'oa gspszrsm ATT RNEY June 6, 1967 B. EPSZTEIN 3,324,341

. HIGH POWER ELECTRON TUBE WITH MULTIPLE LOCKED-IN MAGNFTRON OSCILLATORS Flled Nov 14 1961 7 Sheets-Sheet 7 lNVENTOR a. EPSZT'E/N ATTOR EY United States Patent Claims. e. 315--3.6)

The present invention relates to travelling wave amplifiers and aims at obtaining from such an amplifier power levels very much superior to those delivered by the known amplifiers of the prior art. Additionally, the present invention also aims at a simple construction for such an amplifier.

The power delivered by an amplifier is obviously the higher the more one succeeds in realizing a higher efficiency of the system and a larger capacity of dissipation of the losses within the anode circuit.

It is known that the limitations imposed by one or the other of these factors determine the limitation of the order of magnitude of the power which it is possible to obtain actually with travelling wave amplifiers. On the other hand, it is known that microwave tubes incorporating the magnetron structure such as magnetron oscillators, magnetron travelling wave amplifiers, amplitrons, etc., have a high efiiciency, characteristic of this structure. Finally, travelling wave amplifiers are known in which the capacity of dissipation of the anode circuit has been increased by the use of a bi-dimensional periodic circuit.

According to the present invention, one way which permits of an increase in the power beyond the limits permitted by the actual amplifiers, is opened up by associating in one and the same system the principle of the magnetron structure with that of the bidimensional circuit, and in particular by disposing alongside one another, a plurality of elementary magnetrons with mutual couplings and by combining the anode circuits thereof in such a manner as to constitute a bi-dimensional network with polygonal meshes, this network being excited by the wave to be amplified which causes the magnetrons to oscillate in the manner of locked-in oscillators. The power supplied by the magnetrons is cumulative and is collected in the output circuit thereof.

According to one advantageous embodiment of the present invention, the anode elements of the magnetrons which form a bi-dimensional network are supported by a common plate in such a manner as to form a herse-like structure whereas a second herse-like structure is formed by the cathodes of the magnetrons disposed in the manner of a bi-dimensional network on a second common plate. These two herses are interleaved in an interdigital manner in such a way that each cathode finds itself in the center of a mesh or cell of the anode network.

The cathodes are preferably of the cold emission-type.

According to a further characteristic of the present invention, the plates of the two herses have a trapezoidal form or essentially triangular form, whereby the input circuit of the amplifier is coupled on the side of the small base of the trapezoid and the output circuit on the side of the large base thereof. The tube is thus flared from the input to the output thereof which permits maintaining throughout the entire structure a power density which remains essentially constant.

According to a further development in accordance with the present invention, the axis of propagation of the input energy is inclined with respect to the output window. A portion of the anode circuit is covered by an attenuation so as to absorb the fraction or portion of the energy reflected from the output window.

Appropriate cooling means are advantageously pro vided for the anode elements.

Accordingly, it is an object of the present invention to provide an electron discharge device, and more particularly an amplifier tube which permits attainment of power outputs far superior to those feasible with present day amplifier structures.

Another object of the present invention resides in the provision of an amplifier discharge device which is relatively simple in construction notwithstanding the extremely high power outputs that may be derived therefrom.

A further object of the present invention resides in the provision of a travelling wave tube amplifier which combines certain features of the magnetron type structure with those of a travelling wave tube structure in order to provide a bi-dimensional system and therewith permit an increase in the power levels of the tube.

Still a further object of the present invention resides in the provision of an amplifier device utilizing magnetron-type structures and bi-dimensional travelling wave tube principles to increase the power levels at which the tubes may be operated and which utilizes in particular a bi-dimensional anode circuit for that purpose.

Another object of the present invention resides in the provision of a magnetron-type travelling wave tube amplifier of very high power in which the power density is maintained essentially constant throughout the tube and in which the danger of malfunction or inadequate performance by reason of failure on the part of one or the other elements is substantially minimized.

These and other objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, several embodiments in accordance with the present invention, and wherein FIGURE 1 is a partial plan view of a first embodiment of an anode circuit in accordance with the present invention;

FIGURE 2 is a partial perspective view of an electrode assembly including the anode circuit of FIGURE 1 and the cathode herse-like structure interleaved therewith in accordance with the present invention;

FIGURE 3 is a partial plan view of a second embodiment of an anode circuit in accordance with the present invention;

FIGURE 4 is a partial perspective view of a nelectrode assembly including the anode circuit of FIGURE 3 and the cathode herse-like structure interleaved therewith in accordance with the present invention;

FIGURE 5 is a partial transverse cross sectional view through a third embodiment of an anode circuit in accordance with the present invention;

FIGURE 6 is a partial plan view of the anode circuit illustrated in FIGURE 5;

FIGURE 7 is a partial plan view, similar to FIGURE 6, of a fourth embodiment of an anode circuit in accordance with the present invention;

FIGURE 8 is a perspective view, partly broken away, of an electron tube in accordance with the present invention;

FIGURE 9 is a cross sectional view taken along line XX of FIGURE 8;

FIGURE 10 is a cross sectional view taken along line Y-Y of FIGURE 8;

FIGURE 11 is a cross sectional view, similar to FIG- URE 10, of a modified embodiment of a tube in accordance with the present invention, and

FIGURE 12 is a partial cross sectional view illustrating a detail of a modified embodiment of an anode circuit in accordance with the present invention provided with cooling means.

Referring now to the drawing wherein like reference numerals are used throughout the various views to designate corresponding parts, and more particularly to FIG- URES 1 and 2, reference numeral 1 designates in these two views a metallic plate, for example, of copper which supports a system of metallic rods such as 2, 3, 4 and 5, perpendicular to the plate 1 and disposed in bi-dimensional network which, is, in the embodiment of these two figures, of square meshes. These rods 2, 3, 4 and 5 may be made of any material known in connection with the realization of the fingers of interdigital lines or analogous lines. The assembly of plate 1 and of the network of the rods forms the anode circuit or anode herse. There may be seen additionally, in FIGURE 2, a metallic plate 6, for example, made of copper which supports a system of cathodes 7, for example, of the cold emission type, disposed in bi-dimensional network of the same characteristics as the network of the anode rods. These cathodes 7 may be of any material known for its good coefficient of secondary emission, such as a copper-beryllium alloy. The assembly of the plate 6 and of the cathodes 7 forms the cathode herse. The two anode and cathode herses are interleaved in an interdigital manner in such a way that each cathode 7 is placed at the center of a mesh of the network of rods, such as the mesh formed by the rods 2, 3, 4 and 5.

In the modified embodiment of FIG-URES 3 and 4, in which the same reference numerals designate again elements analogous to those of the preceding figures, the configuration of the meshes of the network of rods is no longer square but is now hexagonal. Each mesh is, therefore, limited by six rods such as rods 2, 3, 4, 5, 8 and 9. Another difference with respect to the preceding embodiment, given only as an example of the different possibilities, is the fact that the anode rods are provided with enlargements such as 10 which in this Case are simple circular heads. The configuration and the pitch of the network of the cathodes have to be selected naturally in such a manner that the cathodes 7 are at the centers of the hexagonal meshes of the anode network when the two herses are interleaved.

FIGURES 5 and 6 illustrate how it is possible, by suitably shaping the heads 10, in obtaining a bi-dimensional network of which the structure of the meshes is that of the multi-cavity-type magnetrons, placed alongside one another and coupled with each other, for example, with six cavities. For that purpose, it is suflicient to give to the head 10 a form of a diamond cut along the four sides thereof by arcs of circle. As may be seen in FIG- URE 6, there are provided the cavities 11 and the gaps 12 which couple the same to the different interaction spaces 13 about the cathodes 7.

The same magnetron structure may be realized in a slightly different maner. Whereas in FIGURE 6, one and the same cavity 11 belongs simultaneously to several, in particular, to three elementary magnetrons, FIGURE 7 illustrates a modified embodiment in which the cavities of each elementary magnetron are separate from those of the adjacent magnetrons and are only coupled with the latter by grooves such as 14. In this embodiment of hexagonal configuration, it suffices to utilize for this purpose rod-heads of two types, the one type 10' having an essentially elongated hexagonal shape provided with six pockets in the shape of an arc of circle, the other type 10" having a substantially triangular shape. The other reference numerals having the same significance, FIG- URE 7 represents in the final analysis, as F-IGURE6, a bi-dimensional network having hexagonal meshes of which each represents the magnetron structure with six cavities, these elementary magnetrons being arranged side by side with mutual or reciprocal couplings.

It is obvious that the principles exposed hereinabove of the formation and construction of bi-dimensional networks which may be used with the present invention are not limited to the square or hexagonal configurations which have been described and shown herein only as illustrative examples for the present invention but are also applicable to other polygonal configurations which may be established in accordance with the needs and requirements therefor. More particularly, the system provided with rods of sectional shape according to FIG- URES 5 to 7 may be adapted to the square configuration with round rods of FIGURES 1 and 2.

FIGURES 8 through 10 illustrate an amplifier tube which may be realized with any one of the anode circuits described hereinabove or their equivalents, and showing for illustrative purposes only the principle of the rods of sectional shape of FIGURES 5 to 7 adapted to the square configuration of FIGURES l and 2. The support 1 of the anode herse is incorporated into the walls of a vacuumtype evacuated box-like enclosure 15, for example, made of copper, coupled on one side thereof to the input guide 16 through an insulating input window 17, and on the other side thereof, to the output horn 18 across an insulating output window 19. The support 6 of the cathode herse is supported on the inside of the box-like closure 15 by insulating columns 20 (FIG. 9). The cathodes 7 engage into the meshes of the anode circuit as shown in FIG- URES 2 or 4. A suitably dimensioned cavity 21 is provided Within the mass of the support 6 and along its periphery, the cavity 21 being dimensioned to form a trap with a view to short-circuit, from a high frequency point of view, the plate 6 with the box-like enclosure 15 and to avoid thereby the propagation of energy within the space between the walls 15 and 6. The height of the rods 2 and of cathodes 7 decreases progressively at the extremities of the circuit toward the input and the output thereof, in accordance with usual matching techniques. The mass of the box like structure 15, and consequently the anode herse, is connected to ground and to the positive pole of the supply source 22 whereas the cathode herse is connected to the negative pole of this source 22 (FIG. 9). The passage of the supply of the cathode herse across the walls of the box-like enclosure 15 is designated by reference numeral 23 in FIGURES 8 and 10. Finally, a magnet 24, for example, a permanent magnet of U- shape, is disposed about the box-like structure 15 in such a manner that the pole pieces N and S furnish a magnetic field directed along the cathodes 7 and rods 2 for operation of the elementary magnetrons incorporated into the anode circuit.

As shown in particular in FIGURE 10, the box-like enclosure 15 is flared from the input to the output thereof, that is the plates 1 and 6 have an essentially triangular or more correctly trapezoidal shape. The ratio of the lengths of the two bases of the trapezoid will be made perferably equal to the order of magnitude of the ratio between the output power and the input power that is, to the gain of the amplifier.

In the further development illustrated in FIGURE 11, the alignment of the rods 2 which coincides with the axis of the input guide 16 and which is perpendicular to the input window 17, is inclined with respect to the output window 19. Additionally, a portion of the anode circuit disposed within the shaded zone 25, that is, outside of the flared zone between the input window and the output window, is covered by an attenuation constituted by any suitable material or by any suitable known internal or external means. Otherwise, the tube of FIGURE 11 is similar to that of FIGURES 8 through 10 described hereinabove.

FIGURE 12 represents a modified construction of the anode circuit provided with cooling means. The rods 2 are hollow and closed at the end whereas the plate 1 is provided with a cooling jacket 26, a channel network with input means at 27 and output means at 28 being established across the jacket 26 and the rods 2 to permit the circulation of a refrigerating liquid.

OPERATION Having thus described the structures of amplifiers in accordance with the present invention, the operation thereof will now be described.

Since the voltage of the source 22 is applied between the anode herse and the cathode herse, that is, since a direct-current electric field is setup between each rod 2 and a respective cathode 7, and since the magnetic field of the magnet 24 traversing the interior space of the boxlike enclosure 15 is perpendicular to this electric field, the high frequency wave supplied through the guide 16 and entering through window 17 provides for the appear ance of two phenomena. On the one hand, the intensive field of the incident Wave in combination with the directcurrent field excites or produces the cold emission of each of the cathodes according to the well known mechanism. On the other hand, if it is assumed that the wave is plane and propagates along the diagonal of each mesh of the bidimensional network, and if the wave-length propagated by the delay circuit, that is, the incident wave-length reduced within the proportion of the delay ratio of the circuit, is approximately i.e., within the limits of a certain band, equal to the dimension of this diagonal, then the elementary magnetrons of the system commence to oscillate at the frequency of the incident wave and oscillate in the manner of a locked-in oscillation system in accordance with the mode which depends on the number of anode elements of the magnetron. For example, within a system with four elements, and assuming the wave length propagated within the circuit to be equal to the diagonal p of the mesh 2, 3, 4, 5 of FIGURE 1, this wave advancing along the diagonal from 3 to 2, there may be taken as reference, that is, phase zero, the phase of the wave at the moment when it has reached the element 2 and at the level of the latter. At that moment, the phase at the level of the element 3 will be Zr, and at the level of each of the elements 4 and 5 will be 11'. It may, therefore, be seen that the phase difference between the voltages of each pair of adjacent peripheral elements in the magnetron having as anode the elements 2, 3, 4 and 5 is equal to 1r. This magnetron finds itself therefore in condition of oscillation in the so-called 1r-mode. Analogous considerations will show the possibility of oscillation, in other modes, of the magnetrons provided with hexagonal or other polygonal anode systems.

The respective phases of the waves generated by the elementary oscillators are such that only the energy propagated in the same direction as the incident wave has a resultant which is not equal to zero whereas the energy propagated in the other direction is effectively destroyed by interference, i.e., effectively annulled by interaction in the system. It follows therefrom that the incident wave, to the extent of its progress within the periodic structure, will be amplified by cumulative action with the energies of the elementary oscillators, to leave through window 19 and to be radiated through the horn 18.

The flared shape of the tube from the input to the output thereof permits to preserve within the entire structure a density practically constant, that is, the same dissipation in each of the anode elements of the circuit. This constancy is assured in a particularly exact manner if the ratio of the dimensions of the circuit at the input and at the output is equal to the gain in power realized within the amplifier.

The improved form of FIGURE 11 aims at eliminating a possible shortcoming which would result from the imperfect matching of the output circuit inclusive the insulating window, and from the reflection of a portion of the amplified energy from this window. This reflected energy, by propagating in a backward direction across the circuit, would then be amplified to the same extent as the normal wave which could introduce a feedback in the circuit and give rise to the auto-oscillation of the tube. In FIGURE 11, the reflected portion of the energy is returned, by the window 19 inclined with respect to the direction of propagation of the wave along the guide 16, toward an attenuated region 25 as indicated by the arrows 29 and 30. The reflected portion is therefore absorbed 0n the inside of the tube which avoids the inconvenience and shortcomings indicated hereinabove.

In order to enable evaluation of the possibilities of the amplifier according to the present invention, there will be given the following example of typical dimensions of a tube in accordance with the present invention.

If it is assumed that the amplifier is to operate in the 10 cm. band with a circuit in accordance with FIGURES 1 and 2, realized with a delay ratio of 20, then the following dimension may be used:

Mm. Diagonal of the meshes p 5 Diameter of the rods 2 2 Length of the rods 2 20 Diameter of the cathodes 7 1 Without artificial cooling, one may admit of a dissipation of 20 watts per rod 2, in which case the temperature is lower than 250 C. If one desires to dissipate 500 kilowatts within the circuit, then 25,000 rods are necessary therefor.

If each rod is in the center of a surface of 0.25 cm. the circuit will occupy an area of 6,250 cm. and the plates 1 and 6 may therefore have the shape of a trapezoid with the bases thereof, for example, of one meter and 10 centimeter and with a height of 1.2 meters.

By assuming the typical efiiciency of the magnetron to be 2/3, the dissipated power of 500 kilowatts will correspond to a total applied power of 1,500 kilowatts and to and to an average useful continuous power of 1,000 kilowatts. With a utilization coeflicient of 1/50, the peak power of such tube may be 50 megawatts.

If the circuit is cooled with water, as illustrated in FIG- URE 12, the permissive dissipation is no longer 20 watts but at least 200 or 250 watts per rod. To dissipate the same power of 500 kilowatts, 2,000 rods will therefore suffice which will cover a surface or area of 500 cm. in the form, for example, of a trapezoid with a base of 30 centimeters and 3 centimeters, respectively, and with a height of 30 centimeters.

The same useful peak power will then be supplied by 2,000 elementary magnetrons of 25 kilowatts peak power each which will absorb each 37.5 kilowatts peak power, which in turn may be realized with a relatively low voltage from the source 22 of 12.5 kilovolts and with a peak current of 3 amperes per cathode.

The present invention offers numerous advantages of which the following will be mentioned, it being understood that this enumeration is not to be construed as being complete or limitative in any way of the present invention.

(a) Since the energy density may be constant within the entire assembly of the tube, the dangers of melting are therefore very greatly diminished.

(b) The efliciency is the same as those of magnetrons and amplitrons and the band width is that of travelling wave tubes.

(0) The applied voltages are relatively very low so that the dangers of breakdown or arcing are effectively eliminated.

(d) To obtain a high power, it sufiices to take a large surface with the only condition that the energy density remains comprised within certain limits. A suitable law of variattion of the size of the tube from the input to the output permits to aid in satisfying this condition.

(e) It is not essential at all for the proper operation of the tube that the line be uniform. For example, it is possible to suitably vary the pitch of the line within the region of interaction and to thus obtain directional effects analogous to those obtained with microwave lenses.

(f) The local irregularities have a practically negligible importance. Even if some of the cathodes would cease to operate, the performances of the tube would not be affected thereby.

While I have shown and described several embodiments in accordance with the present invention, it is understood that the same is not limited to the details described and shown herein, but may be modified in any suitable manner within the scope of a person skilled in the art. For example, hot cathodes could be substituted for the cold cathodes, and the configurations indicated for the delay circuit could be replaced by other equivalent polygonal configurations.

Since, in a general way, the present invention encompasses all the very high power travelling wave amplifiers which may be realized according to the principles described herein, I do not wish to be limited to the details shown and described herein, but intend to cover all such changes and modfications as are encompassed by the scope of the appended claims.

I claim:

1. A high power microwave travelling wave amplifier, comprising within an evacuated enclosure a plurality of magnetron structures each having cathode means and anode circuit means, said structures being located side by side, means for reciprocally coupling each of said structures with its adjacent structures, said anode circuit means of said structures being combined to effectively form a bi-dimensional network with polygonal meshes, means for applying a potential difference between said anode circuit means and cathode means, means for applying a magnetic field subtantially in the axial direction of said magnetron structures, input means for exciting one side of said network with microwave energy, and output means for abstracting amplified microwave energy at the other side of said network.

2. A high power microwave travelling wave amplifier, comprising within an evacuated enclosure a plurality of magnetron structures each having cathode means and anode circuit means, said structures being located side by side, means for reciprocally coupling each of said structures with its adjacent structures, said anode circuit means of said structures being combined to effectively form a bidimensional network with polygonal meshes, means for applying a potential difference between said anode circuit means and cathode means, means for applying a magnetic field substantially in the axial direction of said magnetron structures, input means for exciting one side of said network with microwave energy, and output means for abstracting amplified microwave energy at the other side of said network, said anode circuit means including first metallic plate means for supporting thereon the elements forming the bi-dimensional anode network, said cathode means including second metallic plate means for supporting thereon the elements forming the bi-dimensional cathode network, and said bi-dimensional anode and cathode networks being interleaved so that each cathode element is located within a respective one of said anode network meshes.

3. A high power microwave travelling wave amplifier, comprising within an evacuated enclosure a plurality of magnetron structures each having cold-emission cathode means and anode circuit means, said structures being disposed in juxtaposition, means for reciprocally coupling said structures, said anode circuit means of said structures being combined to effectively form a bi-dimensional network, means for applying a potential difference between said anode circuit means and cathode means, means for applying a magnetic field substantially in the axial direction of said magnetron structures, input means to enable application of microwave energy to one side of said network and output means to enable abstracting amplified microwave energy at the other side of said bi-dimensional network.

4. A high power microwave travelling wave amplifier, comprising within an evacuated enclosure a plurality of magnetron structures each having cathode means and anode circuit means, said structures being located side by side, means for reciprocally coupling each of said structures with its adjacent structures, said anode circuit means of said structures being combined to effectively form a bidimensional network with polygonal meshes, means for applying a potential difference between said anode circuit means and cathode means, means for applying a magnetic field substantially in the axial direction of said magnetron structures, input means for exciting one side of said network with microwave energy, and output means for abstracting amplified microwave energy at the other side of said network, said anode circuit means including first metallic plate means for supporting thereon the elements forming the bi-dimensional anode network, said cathode means including second metallic plate means for supporting thereon the elements forming the bi-dimensional cathode network, said second metallic plate means being substantially parallel to and electrically insulated with respect to said first metallic plate means, and said bidimensional anode and cathode networks being interleaved so that each cathode element is located within a respective one of said anode network meshes, said plate means having a substantially trapezoidal shape, said input means being operative to apply the microwave energy to the side forming the small base of the trapezoid and said output means effectively abstracting the amplified microwave energy from the side forming the large base of the trapezoid.

5. A high power microwave travelling wave amplifier, comprising within an evacuated enclosure a plurality of magnetron structures each having cathode means and anode circuit means, said structures being located side by side, means for reciprocally coupling each of said structures with its adjacent structures, said anode circuit means of said structures being combined to effectively form a bidimensional network with polygonal meshes, means for applying a potential difference between said anode circuit means and cathode means, means for applying a magnetic field substantially in the axial direction of said magnetron structures, input means for exciting one side of said network with microwave energy, and output means for abstracting amplified microwave energy at the other side of said network, said anode circuit means including first metallic plate means for supporting thereon the elements forming the bi-dimensional anode network, said cathode means including second metallic plate means for supporting thereon the elements forming the bi-dimensional cathode network, said second metallic plate means being substantially parallel to and electrically insulated with respect to said first metallic plate means, and said bi-dimensional anode and cathode networks being interleaved so that each cathode element is located within a respective one of said anode network meshes, said plate means having a substantially trapezoidal shape, said input means being operative to apply the microwave energy to the side forming the small base of the trapezoid and said output means effectively abstracting the amplified microwave energy from the side forming the large base of the trapezoid, the ratio of the lengths between said large base and said small base being substantially equal to the power gain of the amplifier.

6. A high power microwave travelling wave amplifier, comprising within an evacuated enclosure a plurality of magnetron structures each having cathode means and anode circuit means, said structures being disposed in juxtaposition, means for reciprocally coupling said structures, said anode circuit means of said structures being combined to effectively form a bi-dimensional network, means for applying a potential difference between said anode cir- 9 cuit means and cathode means, means for applying a magnetic field substantially in the axial direction of said magnetron structures, input means to enable application of microwave energy to one side of said network, and output means to enable abstracting amplified microwave energy at the other side of said bi-dimensional network.

7. A high power microwave travelling wave amplifier, comprising within an evacuated enclosure a plurality of magnetron structures each having cathode means and anode circuit means, said structures being disposed in juxtaposition, means for reciprocally coupling said structures, said anode circuit means of said structures being combined to effectively form a bi-dimensional network, means for applying a potential difference between said anode circuit means and cathode means, means for applying a magnetic field substantially in the axial direction of said magnetron structures, input means to enable application of microwave energy to one side of said network and output means to enable abstracting amplified microwave energy at the other side of said bi-dimensional network, the pitch of said bi-dimensional anode network being substantially equal to the wave-length of the microwave energy propagating therein which is supplied thereto by said input means.

8. In a microwave amplifier tube of the travelling wave type having an evacuated enclosure, an anode structure along which electromagnetic microwave energy may propagate and provided with input means and output means, and a cathode structure for emitting electrons adapted to move within said tube in energy-transfer relationship with the electromagnetic wave energy adapted to propagate in said anode structure, the improvement essentially consisting of a plurality of magnetron-like structures within said enclosure, each magnetron-like structure comprising first means effectively forming an anode circuit and second means effectively forming a cathode, and means within said tube for effectively coupling adjacent magnetron-like structures with each other to efiectively form bi-dimensioual network means constituted at least in part by said anode circuits along which propagates the microwave energy supplied by said input means to enable abstraction thereof by said output means after amplification thereof within said tube.

9. A high power microwave travelling wave amplifier, comprising within an evacuated enclosure a plurality of magnetron structures each having cathode means and anode circuit means, said structures being disposed in juxtaposition, means for reciprocally coupling said structures, said anode circuit means of said structures being combined to effectively form a bi-dimensional network, cooling means for said bi-dimensional anode network, means for applying a potential difference between said anode circuit means and cathode means, means for applying a magnetic field substantially in the axial direction of said magnetron structures, input means to enable application of microwave energy to one side of said network, and output means to enable abstracting amplified microwave energy at the other side of said bi-dimensional network.

10. A high power electron discharge device of the travelling wave type which is adapted to amplify electromagnetic wave energy, comprising first means effectievly constituting an anode structure, second means effectively constituting a cathode structure, said first and second means being so assembled and arranged as to form a plurality of magnetron-like structureshaving anode and cathode means, at least the anode means of said magnetronlike structures effectively constituting a bi-dimensional network provided with means efiectively and reciprocally coupling the magnetron-like structures, input means for said network to enable the application thereto of microwave energy, and output means coupled to said network for abstracting therefrom amplified microwave energy.

11. A high power microwave travelling wave amplifier, comprising within an evacuated enclosure a plurality of magnetron structures each having cathode means and an anode circuit means, said structures being juxtaposed, maens for reciprocally coupling said structures, at least the anode circuit means of said structures being combined to effectively form a bi-dimensional network with poly onal meshes, means for applling a potential difference between said anode circuit means and cathode means, means for applying a magnetic field substantially in the axial direction of said magnetron structures, input means to enable exciting one side of said network with microwave energy, and output means to enable abstracting amplified microwave energy at the other side of said network including an output window inclined with respect to the direction of propagation within said anode network of microwave energy supplied by said input means.

12. In a microwave amplifier tube of the travelling wave type having an evacuated enclosure, an anode struc ture along which electromagnetic microwave energy may propagate and provided with input means and output means, and a cathode structure for emitting electrons adapted to move within said tube in energy-transfer relationship with the electromagnetic wave energy adapted to propagate in said anode structure, the improvement essentially consisting of a plurality of magnetron-like structures within said enclosure, each magnetron-like structure comprising first means effectively forming an anode circuit and second means effectively forming a cathode, and means within said tube for effectively coupling adjacent magnetron-like structures with each other to effectively form bi-dimensional network means constituted at least in part by said anode circuit along which propagates the microwave energy supplied by said input means to enable abstraction thereof by said output means after amplification thereof within said tube, and means within said tube for maintaining substantially constant throughout the active part of the tube the energy density.

13. A high power microwave travelling wave amplifier, comprising within an evacuated enclosure a plurality of magnetron structures each having cathode means and an anode circuit means, said structures being juxtaposed, means for reciprocally coupling said structures, at least the anode circuit means of said structures being combined to effectively form a bi-dimensional network with poly onal meshes, means for applying a potential difference between said anode circuit means and cathode means, means for applying a magnetic field substantially in the axial direction of said magnetron structures, input means to enable exciting one side of said network with microwave energy, output means to enable abstracting amplified microwave energy at the other side of said'network including an output window inclined with respect to the direction of propagation within said anode network of microwave energy supplied by said input means, and attenuating means operatively associated with that part of said anode network which lies in the path of the portion of microwave energy reflected by said output window.

14. A high power microwave travelling wave amplifier, comprising within an evacuated enclosure a plurality of magnetron structures each having cathode means and an anode circuit means, said structures being juxtaposed, means for reciprocally coupling said structures, at least the anode circuit means of said structures being combined to effectively form a bi-dimensional network with polygonal meshes of square shape, means for applying a potential difference between said anode circuit means and cathode means, means for applying a magneticfield substantially in the axial direction of said magnetron struc tures, input means to enable exciting one side of said network with microwave energy, and output means to enable abstracting amplified microwave energy at the other side of said network.

15. A high power microwave travelling wave amplifier, comprising within an evacuated enclosure a plurality of magnetron structures each having cathode means and an anode circuit means, said structures being juxtaposed, means for reciprocally coupling said structures, at least the anode circuit means of said structures being combined to effectively form a bi-dimensional network with polygonal meshes of hexagonal shape, means for applying a potential difference between said anode circuit means and cathode means, means for applying a magnetic field substantially in the axial direction of said magnetron structures, input means to enable exciting one side of said network with microwave energy, and output means to enable abstracting amplified microwave energy at the other side of said network. a

16. A high power microwave travelling wave amplifier, comprising within an evacuated enclosure a plurality of magnetron structures each having cathode means and an anode circuit means, said structures being juxtaposed, means for reciprocally coupling said structures, at least the anode circuit means of said structures being combined to effectively form a bi-dimensional network with polygonal meshes, the elements of said network having the form of rods supporting thereon profiled heads, means for applying a potential difference between said anode circuit means and cathode means, means for applying a magnetic field substantially in the axial direction of said magnetron structures, input means to enable exciting One side of said network with microwave energy, and output means to enable abstracting amplified microwave energy at the other side of said network.

17. A high power electron discharge device adapted to amplify electromagnetic wave energy, comprising, within a substantially evacuated enclosure, anode means and cathode means, said anode and cathode means being so arranged as to effectively form simultaneously, on the one hand, a plurality of magnetron-like structures each provided with an anode structure with a cathode structure and, on the other, a bi-dimensional wave-guiding structure along which microwave energy is adapted to propagate, input and output means for said wave-guiding structure to enable application to and abstraction from said wave guiding structure of microwave energy, and means for amplifying within said device the applied microwave energy including means for operating said magnetron-like structures substantially as mutually coupled locked-in oscillators controlled by the applied microwave energy and means enabling propagation of the applied microwave energy along said wave guiding structure in energy transfer relationship with the microwave energy produced by said magnetron-like structures in such a manner as to produce an increase in the energy level of said propagating microwave energy.

18. A high power electron discharge device of the travelling wave type which is adapted to amplify electromagnetic wave energy, comprising first means effectively constituting an anode structure including means effectively providing a bi-dimensional travelling-wave structure, second means effectively constituting a cathode structure including electron emissive means, said first and second means being so assembled and arranged as to form a plurality of magnetron-like assemblies, means effectively coupling individual magnetron-like assemblies with each other, input means to enable application of microwave energy to said bi-dimensional structure, and output means coupled to said bi-dirnensional structure for abstracting therefrom amplified microwave energy.

19. A high power microwave travelling wave amplifier, comprising with an evacuated enclosure a plurality of magnetron structures each having cathode means and anode circuit means, said structures being located side by side, means for reciprocally coupling each of said structures with its adjacent structures, said anode circuit means of said structures being combined to effectively form a bi-dimensional network with polygonal meshes, means for applying a potential difference between said anode circuit means and cathode means, means for applying a magnetic field substantially in the axial direction of said magnetron structures, input means for exciting one side of said network with microwave energy, and output means for abstracting amplified microwave energy at the other side of said network, said anode circuit means including first metallic plate means for supporting thereon the elements forming the bi-dimensional anode network, said cathode means including second metallic plate means provided with at least one trap for microwave energy for supporting thereon the elements forming the bi-dimensional cathode network, said second metallic plate means being substantially parallel to and electrically insulated with respect to said first metallic plate means, and said bi-dimensional anode and cathode networks being interleaved so that each cathode element is located within a respective one of said anode network meshes.

20. A high power electron discharge device adapted to amplify electromagnetic wave energy, comprising, within a substantially evacuated enclosure, anode means and cathode means, said anode and cathode means being so arranged as to effectively form simultaneously, on the one hand, a plurality of magnetron-like structures each provided with an anode structure with a cathode structure and, on the other, a bi-dimensional wave-guiding structure along which microwave energy is adapted to propagate, input and output means for said wave-guiding structure to enable application to and abstraction from said wave guiding structure of microwave energ, and means for amplifying within said device the applied microwave energy including means for operating said magnetron-like structures substantially as mutually coupled locked-in oscillators controlled by the applied microwave energy and means enabling propagation of the applied microwave energy along said wave guiding structure in energy transfer relationship with the microwave energy produced by said magnetron-like structures in such a manner as to produce an increase in the energy level of said propagating microwave energy while maintaining essentially constant the energy density within said device.

21. A high power microwave travelling wave amplifier, comprising within an evacuated enclosure a plurality of magnetron structures each having cathode means and an anode circuit means, said structures being located side by side, means for reciprocally coupling said structures, the anode circuit means of said structures being combined to form a bi-dimensional network with polygonal meshes, means for applying a potential difference between said anode circuit means and cathode means, means for applying a magnetic field substantially in the axial direction of said magnetron structures, means to enable exciting one side of said network with microwave energy, and means to enable abstracting amplified microwave energy at the other side of said network, the cathode means and the anode network elements being of progressively decreasing heights in the direction toward both the input and output sides thereof.

22. A high power microwave travelling Wave amplifier, comprising within an evacuated enclosure a plurality of magnetron structures each having cathode means and anode circuit means, said structures being located side by side, means for reciprocally coupling each of said structures with its adjacent structures, said anode circuit means of said structures being combined to effectively form a bi-dimensional network with polygonal meshes, means for applying a potential difference between said anode circuit means and cathode means, means for applying a magnetic field substantially in the axial direction of said magnetron structures, input means for exciting one side of said network with microwave energy, and output means for abstracting amplified microwave energy at the other side of said network, said anode circuit means including first me tallic plate means for supporting thereon the elements forming the bi-dimensional anode network, said cathode means including second metallic plate means provided with at least one trap for microwave energy for supporting thereon the elements forming the bi-dimensional cathode network, said second metallic plate means being substantially parallel to and electrically insulated with respect to said first metallic plate means, and said bi-dimensional anode and cathode networks being interleaved so that each cathode element is located within a respective one of said anode network meshes, said plate means having a substantially trapezoidal shape, said input means being operative to apply the microwave energy to the side forming the small base of the trapezoid and said output means eifectively abstracting the amplified microwave energy from the side forming the large base of the trapezoid, the ratio of the lengths between said large base and said small base being substantially equal to the power gain of the amplifier.

23. A high power microwave travelling wave amplifier, comprising within an evacuated enclosure a plurality of magentron structures each having cathode means and anode circuit means, said structure being located side by side, means for reciprocally coupling each of said structures, said anode circiut means of said structures being combined to effectively form a bi-dimensional network with polygonal meshes, means for applying a potential difference between said anode circuit means and cathode means, means for applying a magnetic field substantially in the axial direction of said magnetron structures, input means for exciting one side of said network with microwave energy, and output means for abstracting amplified microwave energy at the other side of said network, said anode circuit means including first metallic plate means for supporting thereon the elements forming the bi-dimensinal anode network, said cathode means including second metallic plate means for supporting thereon the elements forming the bi-dimensional cathode network, and said bi-dimensional anode and cathode networks being interleaved so that each cathode element is located within a respective one of said anode network meshes, said plate means having a substantially trapezoidal shape, said input means being operative to apply the microwave energy to the side forming the small base of the trapezoid and said output means eifectively abstracting the amplified microwave energy from the side forming the large base of the trapezoid, the ratio of the lengths between said large base and said small base being substantially equal to the power gain of the amplifier.

24. A high power microwave travelling wave amplifier, comprising within an evacuated enclosure a plurality of magnetron structures each having cathode means and an anode circuit means, said structures being located side by side, means for reciprocally coupling said structures, the anode circuit means of said structures being combined to form a bi-dimensional network with polygonal meshes, means for applying a potential difference between said anode circiut means and cathode means, means for applying a magnetic field substantially in the axial direction of said magnetron structures, means to enable exciting one side of said network with microwave energy, and means to enable abstracting amplified microwave energy at the other side of said network, the anode network elements being of progressively decreasing heights in the direction toward both the input and output sides thereof.

25. A high power electron discharge device adapted to amplify electromagnetic wave energy, comprising, within a substantially evacuated enclosure, anode means and cathode means, said anode and cathode means being so arranged as to effectively form simultaneously, on the one hand, a plurality of magnetron-like structures each provided with an anode structure with a cathode structure, and on the other, a bi-dimensional wave-guiding structure along which microwave energy is adapted to propagate, input and output means for said wave-guiding structure to enable application to and abstraction from said wave guiding structure of microwave energy, and means for amplifying within said device the applied microwave energy including means for operating said magnetron-like structures substantially as locked-in oscillators and means enabling propagation of the applied microwave energy along said wave guiding structure in energy transfer relationship with the microwave energy produced by said magnetron-like structures.

References Cited UNITED STATES PATENTS 2,687,777 8/1954 Warneck et al. 315-36 X 2,832,005 4/1958 Brown 31539.3 2,849,643 8/1958 Mourier 31539.3 X 2,888,598 5/1959 Palluel 3153.6 2,888,649 5/1959 Dench et al. 33217 2,951,173 8/1960 Mourier et al. 3153.6 2,992,356 7/1961 Paschke 315-3.6 3,002,123 9/1961 Peter 315-393 FOREIGN PATENTS 1,109,184 9'/1955 France. 1,093,917 12/ 1960 Germany.

OTHER REFERENCES Kline, IRE Transaction on Electron Devices, November 1961, pp. 437-442 (The Magnetron as a Negative- Resistance Amplifier).

Slater: Microwave Electronics (Phasing of a Self- Excited Oscillator by an External Signal), pp. 205 and 206, Van Nostrand, 1950.

HERMAN KARL SAALBACH, Primary Examiner. BENNETT G. MILLER, Examiner.

' s. I. CHATMON, .TR., (3. o. GARDNER,

Assistant Examiners. 

1. A HIGH POWER MICROWAVE TRAVELLING WAVE AMPLIFIER, COMPRISING WITHIN AN EVACUATED ENCLOSURE A PLURALITY OF MAGNETRON STRUCTURES EACH HAVING CATHODE MEANS AND ANODE CIRCUIT MEANS, SAID STRUCTURES BEING LOCATED SIDE BY SIDE, MEANS FOR RECIPROCALLY COUPLING EACH OF SAID STRUCTURES WITH ITS ADJACENT STRUCTURES, SAID ANODE CIRCUIT MEANS OF SAID STRUCTURES BEING COMBINED TO EFFECTIVELU FROM A BI-DIMENSIONAL NETWORK WITH POLYGONAL MESHES, MEANS FOR APPLYING A POTENTIAL DIFFERENCE BETWEEN SAID ANODE CIRCUIT MEANS AND CATHODE MEANS, MEANS FOR APPLYING A MAGNETIC FIELD SUBSTANTIALLY IN THE AXIAL DIRECTION OF SAID MAGNETRON STRUCTURES, INPUT MEANS FOR EXCITING ONE SIDE OF SAID NETWORK WITH MICROWAVE ENERGY, AND OUTPUT MEANS FOR ABSTRACTING AMPLIFIED MICROWAVE ENERGY AT THE OTHER SIDE OF SAID NETWORK. 